MCB 150 EXAM 3 UIUC Exam Advanced
Practice 2026|2027 Questions and Answers
with Complete A+ Solutions 100%
Correct!!!
What do proteins that stay and function in the cytoplasm have? - Correct Answer -no additional
"trageting signals"
What do proteins that are destined to be secreted outside of the cell or function in other
organelles? - Correct Answer -site of translation depends on fate of protein
How can we demonstrate the path a protein takes? - Correct Answer -Palade's pulse chase
experiment
What does pulse chase experiment determine? - Correct Answer -secretory pathway
What is the secretory pathway - Correct Answer -Rough ER-> golgi apparatus -> secretory
vesicles -> exterior
,Function of Rough ER - Correct Answer -plays role in protein secretion, synthesis of membrane
proteins, protein processing
Function of Smooth Er - Correct Answer -plays role in lipid bilayer synthesis, detoxification
What targets translation to the RER? - Correct Answer -Signal hypothesis
Translation at ER membrane - Correct Answer -1. Srp binds to er signal sequence and blocks
translation
2. srp binds to srp receptor; ribosome docks on the membrane
3. gtp binds to srp and srp receptor; pore opens and polypeptide is inserted
4. gtp is hydrolyzed and srp is released
5. signal sequence is cleaved by signal peptidase as polypeptide elongates and translocates into
er lumen
6. completed polypeptide is released into er lumen, ribosome is released, and translocon pore
closes
Single pass transmembrane protein - Correct Answer -N terminus in cytoplasm and C terminus
in lumen OR C terminus in cytoplasm and N terminus in lumen
multipass transmembrane protein - Correct Answer -spans membrane several times, C terminus
in cytoplasm and N terminus in lumen
, Hw do we get a protein into 1 of the 3 types of configuration? - Correct Answer -protein
presents secondary signal?
What about transmembrane proteins with their N terminus on the cytoplasmic side? - Correct
Answer -1. first presented signal is internal signal sequence
2. recognized by srp
3. ribosomes pause
4. move to er
5. dock with srp receptor
6. signal peptide is folded into translocon with N terminus facing cytoplasm and C terminal
facing lumen
7. do not cut off signal sequence
8. ribosome recognizes stop codon
9. stops translating
10. ribosomes dissociate
11. translocon slams shut
12. squeezes out internal sequence which is rejected into membrane
How are multi pass transmembrane proteins made - Correct Answer -1. signal has to be
presented (short stretch of 3 amino acids and one of them is an asp)
2. build oligosaccharide tree (addition of a few sugars onto a lipid soluble molecule, has 14
different monosaccharides in it), every protein that goes through the er gets glycosylated
3. YO WTF
Practice 2026|2027 Questions and Answers
with Complete A+ Solutions 100%
Correct!!!
What do proteins that stay and function in the cytoplasm have? - Correct Answer -no additional
"trageting signals"
What do proteins that are destined to be secreted outside of the cell or function in other
organelles? - Correct Answer -site of translation depends on fate of protein
How can we demonstrate the path a protein takes? - Correct Answer -Palade's pulse chase
experiment
What does pulse chase experiment determine? - Correct Answer -secretory pathway
What is the secretory pathway - Correct Answer -Rough ER-> golgi apparatus -> secretory
vesicles -> exterior
,Function of Rough ER - Correct Answer -plays role in protein secretion, synthesis of membrane
proteins, protein processing
Function of Smooth Er - Correct Answer -plays role in lipid bilayer synthesis, detoxification
What targets translation to the RER? - Correct Answer -Signal hypothesis
Translation at ER membrane - Correct Answer -1. Srp binds to er signal sequence and blocks
translation
2. srp binds to srp receptor; ribosome docks on the membrane
3. gtp binds to srp and srp receptor; pore opens and polypeptide is inserted
4. gtp is hydrolyzed and srp is released
5. signal sequence is cleaved by signal peptidase as polypeptide elongates and translocates into
er lumen
6. completed polypeptide is released into er lumen, ribosome is released, and translocon pore
closes
Single pass transmembrane protein - Correct Answer -N terminus in cytoplasm and C terminus
in lumen OR C terminus in cytoplasm and N terminus in lumen
multipass transmembrane protein - Correct Answer -spans membrane several times, C terminus
in cytoplasm and N terminus in lumen
, Hw do we get a protein into 1 of the 3 types of configuration? - Correct Answer -protein
presents secondary signal?
What about transmembrane proteins with their N terminus on the cytoplasmic side? - Correct
Answer -1. first presented signal is internal signal sequence
2. recognized by srp
3. ribosomes pause
4. move to er
5. dock with srp receptor
6. signal peptide is folded into translocon with N terminus facing cytoplasm and C terminal
facing lumen
7. do not cut off signal sequence
8. ribosome recognizes stop codon
9. stops translating
10. ribosomes dissociate
11. translocon slams shut
12. squeezes out internal sequence which is rejected into membrane
How are multi pass transmembrane proteins made - Correct Answer -1. signal has to be
presented (short stretch of 3 amino acids and one of them is an asp)
2. build oligosaccharide tree (addition of a few sugars onto a lipid soluble molecule, has 14
different monosaccharides in it), every protein that goes through the er gets glycosylated
3. YO WTF
